Solar cell



FIG. 1 is a perspective view of front, top plan and right side of a solar cell showing our new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a top plan view, a bottom view being a mirror image thereof;

FIG. 5 is a right side view, a left side view being a mirror image thereof;

FIG. 6 is an enlarged right side view thereof; and,

FIG. 7 is a front view thereof, show in environmental use.

The broken lines shown represent unclaimed subject matter and form no part of the claimed design. 

The ornamental design for a solar cell, as shown and described. 